Device and method for transferring linear movements

ABSTRACT

The invention relates to a device, a method and the use of the device, for transferring linear movements. The device consists of a hollow cylinder, in which a pressurized space is found, wherein the pressurized space is bounded by a connection flange, which is attached to a terminal opening of the hollow cylinder, and a movable piston flange, which is applied in a pressure-tight manner to the inside of the cylinder wall of the hollow cylinder, and wherein the connection flange and the piston flange are joined together by means of a reversibly deformable component.

The invention relates to a device and a method for transferring linearmovements. In addition, the invention relates to a use of the device.

Intervening in a process that takes place in a vacuum chamber isfrequently associated with an adverse effect on the vacuum in the vacuumchamber.

A linear movement into a vacuum or out from a vacuum is possible with alinear motion leadthrough, an expansion bellows, a pneumatic cylinder, alinear motor and axial guides. Often the known devices lay claim to arelatively large footprint. Also, the movement stroke, which is requiredfor a linear motion leadthrough, an expansion bellows or a cylinder, aswell as the structural length of the individual components are takeninto consideration in the space requirement.

Another disadvantage of the use of linear motion leadthroughs is thatleakage losses occur with these.

Linear motors or pneumatic/hydraulic cylinders are suitable formovements, but not for a relatively long, constant introduction offorces.

Also, an additional guide is necessary in order to transfer forces freeof lateral or crosswise forces to an expansion bellows.

For the generation of the necessary forces, including forces thatcounter air pressure, among others, there are relatively largepneumatic/hydraulic cylinders or electrical motors, which must be joinedin a structurally complex manner with the expansion bellows and thevacuum housing.

The object of the invention is thus to find a simple, space-savingsolution, by means of which linear movements are transferred to regionsof high vacuum with good axial guide precision and without leakagelosses, and a defined holding force can be introduced over a relativelylong time frame.

The object of the present invention is accomplished by a devicecomprising a hollow cylinder, in which a pressurized space is found,wherein the pressurized space is bounded by a connection flange, whichis attached to a terminal opening of the hollow cylinder, and a movablepiston flange, which is applied in a pressure-tight manner to the insideof the cylinder wall (inner lateral surface) of the hollow cylinder, andwherein the connection flange and the piston flange are joined by meansof a reversibly deformable component in the axial direction.

An axial guidance is assured by the device according to the invention.

The device according to the invention operates in a leak-free manner.The integrated method of construction has the advantage that the devicepossesses a small footprint and is also easy to construct.

The reversibly deformable component in the axial direction is preferablycompletely comprised or partially comprised of a good reversiblydeformable material. This material makes it possible to bring about anaxial movement of the piston flange in the hollow cylinder by alongitudinal extension or contraction. The material must be selectedsuch that it does not cave in on itself due to the difference inpressure between the pressurized space and the inside space of thedeformable component.

The inside space, which is formed by the hollow space of the reversiblydeformable component, essentially has the shape of a cylinder,hexahedron, parallelepiped or prism.

In a particularly preferred embodiment of the invention, the reversiblydeformable component is an expansion bellows. Expansion bellows areparticularly well suitable for operating in vacuum, since they barelydeform at all except in the desired longitudinal direction, and wellwithstand a drop in pressure.

The reversibly deformable component, however, may also be constructed ofseveral parts.

In a preferred embodiment, the reversibly deformable component iscomprised of at least three parts, wherein two non-deformable parts areeach joined with one end of a deformable part and one non-deformablepart is joined to the connection flange and the second non-deformablepart is joined to the movable piston flange.

The reversibly deformable component can be extended in the longitudinaldirection and again contracted by means of the deformable part. Thenon-deformable, rigid parts serve for fastening the deformable part ofthe component to the connection flange and the piston flange.

The linear movement is produced by a change in pressure in thepressurized space. Due to a higher pressure in the pressurized space,the component or the reversibly deformable part of the component (forexample, an expansion bellows) is extended longitudinally. If thepressure is reduced, then the component again contracts.

An axial movement of the piston flange in the hollow cylinder, however,may also be invoked by a pressure change in the inside space of thereversibly deformable component.

The force for tightening and holding any component in vacuum can bebuilt up by the atmospheric pressure. The loosening force necessary fora short time is already produced by a slight overpressure in thepressurized chamber. The reversibly deformable component (for example,an expansion bellows) can withstand this overpressure.

The device preferably can be fastened to a container by means of theconnection flange or a terminal end of the hollow cylinder. To do so,the connection flange is attached to the container by means of welding,bonding, screwing, clamping, crimping or other suitable fasteningpossibilities.

Normally, the connection flange serves for joining the device to acontainer. It is also possible, however, that the device enters into apressure-tight connection with a container by one terminal end of thehollow cylinder. Such a connection can join the container and device byanother flange, or can be created by a rigid installation of the devicein or on a container.

The container is preferably a vacuum chamber.

The device according to the invention can be easily fastened to acontainer by the connection flange, for example, by a screw connectionor a bayonet joint or quarter-turn fastener.

The connection flange preferably has an (inner) opening, whereby it ispossible to transfer a movement into the container (or the vacuumchamber).

A standard flange, for example an ISO K or an ISO CF flange can be usedas the connection flange.

Linear movements into a vacuum are made possible by the device accordingto the invention. It is thus possible to conduct movements, such as, forexample, the actuating of a switch or the adjusting of a mirror or thetightening of a part, by means of the device, inside a vacuum chamber.For this, a pin which is attached to the piston flange and whichprojects into the container can serve as the actuator. The pin is guidedlinearly by the device, by the movement of the piston flange, and, bychanging pressure in the pressurized space or in the inside space of thedeformable component, can execute movements in the container such as,for example, actuating a switch or moving samples in the container.

The piston flange preferably also has an (outer) opening. In this way,special flanges can be introduced or electrical or other leadthroughcomponents can be attached.

At least one connection is preferably provided on the piston flange,such as, for example, an ISO K or an ISO CF connection. Flanges suitablefor the specific action can be attached to the piston flange at thisconnection.

In addition, the connection makes it possible for additional equipmentto be flange-mounted to the device.

The flange designations ISO K and ISO CF stand for standardizedconnections in specific nominal widths, but individual flange shapes andflange dimensions may also be used.

The connection is preferably a screw thread, a plug connection, abayonet joint, a screw connection, or another detachable connection witha vacuum seal.

The piston flange forms a pressure-tight connection with the inside ofthe hollow cylinder. In order to seal the sliding piston flange, forexample, the piston flange is provided with peripheral grooves, in whichO-rings are inserted as gaskets. Other seals with surfaces that slideover one another may also be used.

The piston ring of the piston flange can be provided with a materialwith good sliding properties for this purpose. The sliding properties ofthe piston flange can be positively influenced by the use of differentmaterials for the piston gaskets. The piston ring can also be providedwith a lubricant.

The piston flange may also be produced in one piece. The piston flange,however, preferably consists of a piston and at least one flange. Thistwo-part or multi-part embodiment of the piston flange has the advantagethat it facilitates maintenance. In addition, the functionality isthereby increased.

Piston sealing rings serve for the seal between the piston of the pistonflange and the inside of the hollow cylinder.

The cylinder wall of the hollow cylinder preferably has an opening inthe region of the pressurized space. A gas or a liquid can be guidedinto or out from the pressurized space through this opening.

The device according to the invention consists of materials that areable to withstand the pressure fluctuations occurring in the device.Steel, particularly stainless steel, is a suitable material for thehollow cylinder and the flange of the device according to the invention.Other materials known to the person skilled in the art, which aresuitable for the applications described herein, for example, plasticssuch as polytetrafluorethylene (Teflon®), metal alloys such as aluminumor magnesium alloys, and metals such as aluminum can be used for theproduction.

The reversibly deformable component is produced, for example, frommetals such as steel, metal alloys, plastics such as silicone, rubberand/or other materials suitable for the respective application.

The gaskets are produced from metals such as nonferrous metals, plasticssuch as silicone, rubber and/or other materials suitable for therespective application.

The workpieces of the device according to the invention can be milled,turned, stamped, extruded, cast or shaped in another way or can beproduced by means of other methods known to the person skilled in theart.

In addition, the object of the present invention is accomplished by amethod for transferring a linear movement, wherein a movement of thepiston flange in the hollow cylinder is produced by a change in thepressure ratios in the pressurized space and/or in the inside space ofthe reversibly deformable component and/or in the inside space of acontainer connected to the device.

The change in the pressure ratios in the pressurized space is preferablyproduced by introducing or removing a gas or a liquid via the opening inthe cylinder wall.

The change in pressure can be conducted by means of a pump. A gas (forexample, air), a gel or a liquid (for example, a hydraulic oil) can bepumped by means of a pump through the opening in the cylinder wall ofthe hollow cylinder into the pressurized space of the device, wherebythe piston flange is moved away from the container and the reversiblydeformable component is extended. An actuator (e.g., a pin), which isattached directly to the piston flange or is attached via anotherflange, or any other flange is moved with the piston flange and in thisway, the desired linear movement is carried out.

The speed and direction of the linear movement are preferably controlledby adjusting the pressure in the pressurized space. By blowing orpumping the gas or liquid out of the pressurized space, the pressure inthe pressurized space is reduced and the piston flange moves in thedirection of the connection flange. If the pressure in the pressurizedspace is increased, the piston flange moves in the opposite direction(away from the connection flange). The speed with which the gas orliquid is pumped into the pressurized space has an influence on thespeed at which the piston flange moves and thus also how rapidly alinear movement is conducted in the device.

More preferably, the speed and the direction of linear movement arecontrolled by means of adjusting the pressure in the inside space of thereversibly deformable component and/or in the inside space of acontainer connected to the device. By blowing or pumping the gas or theliquid from the inside space of the reversibly deformable componentand/or from the inside space of a container connected to the device, thepressure therein is reduced and the piston flange moves in the directionof the connected container. If the pressure is increased, the pistonflange moves in the opposite direction (away from the connectedcontainer). The speed with which the gas or the liquid is pumped intothe inside space of the reversibly deformable component and/or in theinside space of a container connected to the device, has an influence onthe speed at which the piston flange moves and thus also how rapidly alinear movement is conducted in the device.

In addition, the object of the present invention is accomplished by ause of the device according to the invention for transferring linearmovements into vacuum apparatuses, for example.

The device according to the invention can thus be used as a standardcomponent for vacuum leadthroughs for conducting linear movements.

The invention will be described in more detail below on the basis offigures. Taken individually.

FIG. 1 shows a cross section through a first device according to theinvention,

FIG. 2 shows a cross section through another embodiment of the deviceaccording to the invention,

FIG. 3 shows a three-dimensional representation of the device accordingto the invention shown in FIG. 2, and

FIG. 4 shows another three-dimensional representation of the deviceaccording to the invention shown in FIGS. 2 and 3.

FIG. 1 shows a cross section through a device 1 for transferring linearmovements. Device 1 is comprised of a hollow cylinder 2 and a component3 disposed between a connection flange 5 and a piston flange 7;component 3 consists of two non-deformable parts 11 that are joinedtogether by an expansion bellows 4. In order to create a pressure-tightconnection, the non-deformable parts 11 are welded to connection flange5 and piston flange 7 (welds 19). Other connection possibilities, suchas screws, bonding, soldering or crimping are also suitable.

Connection flange 5 serves for fastening device 1 to a container (forexample, to a vacuum chamber). Connection flange 5 is shaped such thatit makes possible a pressure-tight connection with the vacuum chamber bymeans of a screw connection, a bayonet joint or similar means. Further,connection flange 5 is welded to hollow cylinder 2 (weld 19). Otherconnection possibilities, such as bonding, soldering or crimping arealso suitable. Embodiments are also conceivable, however, in whichconnection flange 5 and hollow cylinder 2 are joined together by othermeans, for example, by a pressure-tight screw connection or a bayonetjoint.

On the inside, connection flange 5 has an opening 14 in the center. Thereversibly deformable component 3 is attached to edge 6 of opening 14.The vacuum-side part 11 of component 3 is joined in a pressure-tightmanner with connection flange 5, for example, by a welded joint (weld19). Other connection possibilities, such as screws, bonding, solderingor crimping are also suitable. It is also possible, however, that thevacuum-side part 11 of the reversibly deformable component 3 is a partof connection flange 5.

The movable piston flange 7 corresponds in its diameter approximately tothat of the inside diameter of hollow cylinder 2, so that piston flange7 can be introduced with an accurate fit into hollow cylinder 2. A pin 8runs through the center of piston flange 7 until it reaches into acontainer connected to device 1.

Piston flange 7 is joined in a pressure-tight manner with pin 8 and theinside of hollow cylinder 2. For this purpose, pin 8 is welded to pistonflange 7 (weld 19). Other connection possibilities, such as screws,bonding, soldering or crimping are also suitable.

On the vacuum side, piston flange 7 is attached to reversibly deformablecomponent 3. Component 3 can be a part of piston flange 7 or can bejoined reversibly with this flange.

Expansion bellows 4 is compressed by an underpressure in pressurizedspace 16. If an overpressure prevails, then expansion bellows 4 extendslongitudinally, so that the pin guided centrally through the entiredevice 1 (expansion bellows cylinder) executes a linear movement.

An overpressure or an underpressure can be built up in pressurized space16 through opening 10 in cylinder wall 9. A pump (for example, a vacuumpump) can be connected to opening 10 for this purpose.

In addition, device 1 can be controlled by a change in pressure in theinside space of the deformable component 3. If device 1 is connected toa container, such as a vacuum chamber, for example, changes in pressurein the container also lead to a movement of piston flange 7.

Therefore, there are two pressurized spaces in which a movement ofpiston flange 7 can be executed by pressure differences.

The hollow space, which is formed between connection flange 5, pistonflange 7, the inside of hollow cylinder 2 and the outside of thereversibly deformable component 3, forms an outer pressurized space 16.

In addition, another hollow space is created by the inside space of thedeformable component 3 and a container connected to device 1. A movementof the piston flange 7 can also be brought about by a change in pressurein this hollow space.

The pressure (or the underpressure), which must be built up for controlin pressurized space 16 and/or in the inside space of component 3, isdependent on the nature of the device, in particular the stability ofcomponent 3.

FIG. 2 shows a cross section through another embodiment of device 1according to the invention with a connection flange 5 and a pistonflange 7.

The connection flange 5 shown in FIG. 2 has a recess 18 for a sealingring. In this embodiment, the piston flange 7 consists of a piston 7-1and a flange 7-2. In the region in which it is applied to the inside ofhollow cylinder 2, piston 7-1 has a piston ring 17, in which O-rings areinserted as gaskets 15. The gaskets create a pressure-tight connectionbetween piston ring 17 of piston 7-1 and the inside of hollow cylinder2. Flange 7-2 has a connection 13 for the uptake of another flange 20.This additional flange 20 is guided coaxially through device 1 by themovement of piston flange 7 in hollow cylinder 2.

Opening 10 of the embodiment shown in FIG. 2 is extended by a tube. Thetube facilitates the connection of lines, with which device 1 can bejoined to a vacuum pump. For this purpose, the tube is joined in apressure-tight manner with cylinder wall 9 of hollow cylinder 2 by aweld 19.

FIGS. 3 and 4 show three-dimensional views of device 1. An opening 10,through which gas or a liquid can be introduced into or removed frompressurized space 16 is found in the region between connection flange 5and piston flange 7 in cylinder wall 9 of hollow cylinder 2.

Device 1 with connection flange 5 points toward the viewer in FIG. 3. Inthe embodiment shown in FIG. 3, connection flange 5 has a recess 18 foruptake of a sealing ring.

Device 1 with piston flange 7 points toward the viewer in FIG. 4. Pistonflange 7 consists of a piston 7-1 and a flange 7-2.

Piston 7-1 forms a pressure-tight connection to the inside of hollowcylinder 2. On the outwardly directed surface of the piston, piston 7-1has connections 13 for fastening another flange or other devices.

Flange 7-2 has an opening 12 in its center. The outer surface of flange7-2 is provided with connections 13.

List of Reference Numbers:

1 Device for transferring linear movements.

2 Hollow cylinder

3 (Reversibly deformable) component

4 Expansion bellows

5 Connection flange

6 Edge (of the inner opening)

7 Piston flange

7-1 Piston

7-2 Flange

8 Pin

9 Cylinder wall

10 Opening

11 Non-deformable part of component 3

12 (Outer) opening

13 Connection

14 (Inner) opening

15 Gasket

16 (Outer) pressurized space

17 Piston ring

18 Recess

19 Weld

20 Flange

1. A device for transferring linear movements, consisting of a hollowcylinder, in which a pressurized space is found, wherein the pressurizedspace is bounded by a connection flange, which is fastened to a terminalopening of hollow cylinder, and a movable piston flange, which isapplied in a pressure-tight manner to the inside of the cylinder wall ofhollow cylinder, and wherein the connection flange and the piston flangeare joined together by means of a reversibly deformable component. 2.The device according to claim 1, further characterized in that thereversibly deformable component is completely or partially comprised ofa reversibly deformable material.
 3. The device according to claim 1,further characterized in that the reversibly deformable component is anexpansion bellows.
 4. The device according to claim 1, furthercharacterized in that the reversibly deformable component is comprisedof at least three parts, wherein two non-deformable parts are eachjoined with one end of a deformable part and one non-deformable part isjoined to the connection flange and the second non-deformable part isjoined to the movable piston flange.
 5. The device according to claim 1,further characterized in that the device can be fastened to a containerby means of connection flange or a terminal end of hollow cylinder. 6.The device according to claim 5, further characterized in that thecontainer is a vacuum chamber.
 7. The device according to claim 1,further characterized in that connection flange has an opening.
 8. Thedevice according to claim 1, further characterized in that connectionflange has an opening.
 9. The device according to claim 1, furthercharacterized in that at least one connection is provided on pistonflange.
 10. The device according to claim 9, further characterized inthat connection is a screw thread, a plug connection, a bayonet joint, ascrew connection, or another detachable connection.
 11. The deviceaccording to claim 1, further characterized in that the piston flange iscomprised of a piston and at least one flange.
 12. The device accordingto claim 1, further characterized in that cylinder wall of hollowcylinder has a opening in the region of pressurized space.
 13. A methodfor transferring a linear movement by means of a device according toclaim 1, wherein a movement of piston flange in hollow cylinder isproduced by a change in the pressure ratios in pressurized space and/orin the inside space of the reversibly deformable component and/or in theinside space of a container connected to device.
 14. The methodaccording to claim 13, further characterized in that the changes of thepressure ratios in pressurized space are produced by introducing orremoving a gas or a liquid through opening in cylinder wall.
 15. Themethod according to claim 13, further characterized in that the speedand direction of the linear movement are controlled by adjusting thepressure in pressurized space.
 16. The method according to claim 15,further characterized in that the speed and direction of the linearmovement are controlled by adjusting the pressure in the inside space ofthe reversibly deformable component and/or in the inside space of acontainer connected to device.
 17. A use of device according to claim 1for transferring linear movements in vacuum apparatuses.